The present invention is applicable to modern saw-gins which are highly automated and productive systems that incorporate many processing stages besides the removal of fibre from seed-cotton.
For instance, typical operation of a modern saw-gin involves opening a module of seed-cotton weighing between 10 and 20 tonnes by a bank of beaters; the seed-cotton is then transported by air through a drying tower that dries the seed-cotton to a moisture level that ensures efficient trash removal. The seed-cotton may be pre-cleaned to remove sticks, stones and unopened bolls before proceeding to a gin stand. At the gin stand, lint is separated from the seed and transported by air to one or two lint cleaners for further cleaning. Following lint cleaning the lint is transported to the battery condenser and the bale press for pressing into a bale.
The roll box of a gin stand is where the actual ginning process, i.e. the separation of cotton fibre (lint) and seed, takes place. The ginning action is caused by multiple circular saws set on a shaft rotating between gin ribs, which are located approximately 1 mm from the saws. The teeth of the saw rake a seed-roll, which is formed in the roll box where in-coming seed-cotton is accumulated. The teeth of the saws pick and hold the fibre on seed-cotton and pass it between the gin ribs at a ginning or gin point or working zone which is substantially adjacent to the saw teeth. The gin point is a zone defined between the leading edge of the saw teeth and the gin rib. At this point the saw teeth pull the lint from the seed, which is too large to pass through the gap between the gin rib and saw, thereby separating the cotton fibre from the seed.
The ginning rib and in particular, the outer face of the ginning rib at the gin point or working zone, which is essentially a planar outer face, is subjected to significant wear and tear. In order to minimize the frequency at which the ginning ribs need replacing, sacrificial inserts or wear plates may be added to the ginning rib at the ginning zone. Like traditional one piece ginning ribs, the inserts also have a planar outer face.